Well, I used to live in Bethel and went through Gorham weekly so I kind of know the area. I thought the roads were ok, not great, but not so bad as to require a dual sport. I'd go Buell, Bandit 1200s, or ZRX1200R. Whatever you get, go used. The depreciation on motorcycles is unreal...
As far as the laptop goes, bring a backpack. There are some really neat motorcycle specific packs out there, and you've got to bring it inside when you get to your destination anyway.